The subject invention provides a forward/aft indicator for an aircraft and more particularly but not by way of limitation for proper positioning underneath a refueling tanker and providing the appearance of an ascending liquid thermometer for guiding the aircraft to be refueled.
In the following U.S. Patents, U.S. Pat. No. 2,777,120 to Madsen, U.S. Pat. No. 3,032,754 to Di Pietro, U.S. Pat. No. 4,170,767 to Tanner and U.S. Pat. No. 4,158,885 to Neuberger an active computer electronic system is described for sequential illumination of tanker aircraft director lights. Also there are various types of disclosures of sequential controlled timing devices for providing a safe standoff between aircraft in the same vicinity. None of the above-mentioned patents disclose the unique features and advantages of a passive type forward/aft indicator as described herein.